This invention relates to a chip conveyer for conveying cutting chips that are produced in the operation of a machine tool, such as a lathe or the like, and contain machine oil from a receiving position to a discharge position, and a chip-separating/recovery apparatus used with the chip conveyer.
As a conventional chip conveyer, the chip conveyer disclosed in Japanese Laid-Open Utility Model Publication No. 59-55645 has been proposed. This chip conveyer includes a circulating conveying member and a bucket removably located at the discharge position of the chips. Chips containing cutting oil are conveyed by the conveying member to the discharge position, and just after the chips reach the discharge position, the chips are received by the bucket. A number of small holes for filtering the cutting oil are provided in the bottom portion of the bucket.
Further, air is sprayed from the outlet of nozzle on the lower surface of the conveying member so that chips that have adhered to the lower surface of the conveying member fall into the bucket. The cutting oil adhered to the chips is recovered through an oil recovery pipe from the number of small holes of the bucket.
On the other hand, the present applicant proposed a chip conveyer disclosed in Japanese Laid-Open Patent Publication No. 63-123656. In this chip conveyer, an endless type mesh belt is provided inside a horizontal frame and an inclined frame. A liquid tank for storing storage liquid is located at the chip receiving position. Chips in the tank are removed by circulation of the belt. A spraying member is arranged between the upper and lower traveling portions of the mesh belt. The spraying member prays cleaning fluid toward the lower traveling portion of the mesh belt, thereby cleaning the lower traveling portion of the mesh belt.
However, the chip conveyer of Japanese Laid-Open Utility Model Publication No. 59-55645 may not reliably isolate and recover chips adhered to the lower surface of the conveying member due to the oil through the air injection from the nozzle. The chips may be separated from the conveying member by raising the pressure of the air injected from the nozzle. However, this requires a structure for preventing the air and chips from being blown away and a supply source of the pressurized air.
Also, in the chip conveyer of Japanese Laid-Open Patent Publication No. 63-123656, the chips cannot be reliably removed by only spraying the cleaning fluid on the mesh belt. Further, not only is a special structure for preventing the flying of cleaning fluid and chips needed, but also a supply source for a high-pressure fluid is needed.
If a piece of a chip is adhered to the conveying member, the chip can enter between sliding parts forming the conveying member to wear the parts. Further, the chip can enter between sliding parts of a mechanism that drives the conveying member, which will degrade the durability of the driving mechanism. Moreover, when the remaining chips fall at the receiving position and accumulate in the bottom of the recovery tank, the accumulated chips must be manually removed frequently.
A screw conveyer may be provided below the recovery tank, which is located at the chip receiving position. However, since the tank is usually provided on the ground, it is necessary to form an underground pit, which greatly increases the installing cost. To prevent the provision of an underground pit, the recovery tank may be located at a position higher than the ground. However, in this case, the machine tool itself, other than the tank, must also be located at a position higher than the ground, which also increases costs greatly. Further, the working position of workpieces becomes higher than necessary and the operation becomes inconvenient.
Some of the chips received by the chip conveyer do not fall in a recovery box at the discharge position but remain adhered to the conveyer and return to the receiving position. The chips are accumulated in the recovery tank at the receiving position. Since the amount of the accumulated chips is relatively large, for example, more than fifty percent in the case of aluminum machining, the recovery tank quickly becomes full. In this case, the machine tool must be stopped to empty the cutting water is emptied and to remove the remaining chips. This must be repeated for, for example, once in two or three days.
To solve this problem, it is an objective of the present invention to provide a chip conveyer that separates and recovers chips from a conveying member by immersing the conveying member in coolant liquid retained in a liquid reservoir, so that the durability of the conveying member and that of a drive mechanism are improved, and suppresses escaping of the chips to a recovery tank, together with a large amount of bubbles generated in the liquid reservoir, when the coolant liquid in the liquid reservoir is new.
In addition to the above, it is another objective of the present invention to provide a chip separation recovery apparatus that has a simple structure and is easily attached to and detached from a discharge portion of a chip conveyer.
To achieve the aforementioned objectives, a preferred embodiment of the present invention provides a chip conveyer including an endless conveying member that circulates in a predetermined direction for receiving chips discharged from a machine tool in a receiving zone, conveying the chips to a discharge position spaced from the receiving zone at a predetermined interval, and discharging the chips at the discharge position. In the chip conveyer, the receiving zone has a predetermined length corresponding to the length of the machine tool. The conveying member travels along a forward route from an end of the receiving zone to a turning point of the conveying member, discharges the chips at the turning point, and travels along a return route from the turning point to a return point where the conveying member is returned to the receiving zone. A liquid reservoir is located at a position corresponding to the return route such that the conveying member enters the liquid reservoir while moving along the return route. This separates the chips adhered to the conveying member in liquid in the liquid reservoir. A liquid supply device for supplying the liquid to the liquid reservoir is provided. A chip discharge means for discharging the separated chips to the exterior is located in the liquid reservoir. A liquid discharge means for discharging excessive liquid is located in the liquid reservoir or the chip discharge means. A suppressing means for suppressing escaping of bubbles from the liquid discharge means is provided.
It is preferred that the conveying member include a scraper and the liquid reservoir include a first liquid reservoir and a second liquid reservoir located below the first liquid reservoir. In this case, the scraper of the conveying member causes the chips separated in the liquid in the first liquid reservoir to fall in the second liquid reservoir, together with the liquid. It is preferred that the second liquid reservoir accommodate the chip discharge means and the liquid discharge means be a liquid discharge pipe connected to the second liquid reservoir.
It is preferred that the suppressing means include a structure that suppresses the escaping of the bubbles by reducing the volume of the liquid in the first liquid reservoir and the surface area corresponding to a liquid level of the first liquid reservoir and a structure that suppresses the escaping of the bubbles by reducing the volume of the liquid in the second liquid reservoir and the surface area corresponding to a liquid level of the second liquid reservoir.
It is preferred that the surface areas corresponding to the liquid levels in the first and second liquid reservoirs be reduced by lowering the liquid levels.
It is preferred that the liquid discharge pipe supply the liquid to the liquid reservoir by means of the conveying member by dropping or spraying the liquid on the conveying member in the return route at an upstream or downstream position with respect to the liquid reservoir.
It is preferred that the conveying member proceed into the liquid of the liquid reservoir through a lowered roundabout route. It is also preferred that the liquid supply device pump the liquid from a recovery tank located in the receiving zone and the liquid discharge means cause excessive liquid to fall in the recovery tank.
Another embodiment of the present invention provides a chip separation recovery apparatus for a chip conveyer. The apparatus includes a liquid reservoir for retaining liquid in which a conveying member is immersed while moving along a return route, a turning mechanism located at a position corresponding to the liquid reservoir for causing the conveying member to take a roundabout route, a chip discharge means for discharging chips retained in the liquid reservoir, a liquid discharge means for discharging excessive liquid from the liquid reservoir, and a suppressing means for suppressing escaping of bubbles from the liquid discharge means.